1. Field of the Invention
The present invention relates to a method of and an electrolytic implement for removing metal pieces such as dental reamers, files or broaches, left in root canals of teeth.
2. Description of the Prior Art
It often happens when carrying out root canal treatment of teeth that a dental appliance such as a reamer, a file, or a broach is broken in a root canal leaving a metal piece. For removal of such residual metal pieces from root canals, there have heretofore been adopted various unpleasant mechanical, chemical and surgical methods.
As an example of a mechanical method presently in use called a Massellan method, the dentine around the residual metal piece is cut off using a special hollow cutting instrument. A special gripping implement is then inserted into the void formed between the residual metal piece and the dentine. Then the top end of the separated metal piece is gripped by the gripping instrument and the metal piece is withdrawn. In this method, the presence and removal should be confirmed by means of radiograph. A long time is required for removal by this method, after a couple of hours. Moreover, application of this method is difficult when the residual metal piece is sharply pointed or the root canal is flat, and if the root canal is curved, this method cannot be applied.
As an example of a chemical method, an iodine method previously practiced uses a potassium iodide or iodine trichloride solution. According to this method, it is necessary to form a by-pass around the residual metal piece to facilitate dissolving the separated metal piece by the solution. Furthermore, if the separated metal piece is relatively large, a long time is required for corrosion of the metal piece and dissolution is often not completed within the time allocated for one treatment. Therefore, in such a case, the chemical solution is sealed in the root canal and after a period of 3 to 7 days, the corroded residual metal piece is removed by a reamer or file. If corrosion is insufficient and such removal by the reamer or file is impossible, the chemical solution is applied again and the above treatment is repeated.
In each of the above-mentioned two methods, a high level of skill is required by the dentist and the patient experiences a lot of discomfort. Moreover, at least several hours are necessary for completion of the removal treatment and in some cases, the treatment extends over 2 or 3 weeks. Furthermore, even after employing these methods, removal is sometimes impossible.